Raised Intersections

Typical Design:

• Raised intersections are flat raised areas elevated three to six inches above the surrounding street grade. The intersection and all adjoining crosswalks are raised. Ramps on the approaches to the intersection are similar to those used on speed tables.
• The Institute of Transportation Engineers has design recommendations.(2)
• The Pennsylvania Department of Transportation has design recommendations.(3)

Placement Issues:

• Raised intersection are appropriate for areas where pedestrian activity is encouraged.
• Avoid placement on arterioles; raised intersections are ideal for residential applications, commercial areas, and business districts.
• Local emergency services should be considered when determining placement. On average, raised intersections cause a 4 to 6 second delay for emergency vehicles.(3)

Approximate Cost:

• Installation costs for a speed hump vary between $15,000 and $60,000 depending on drainage issues, size of the intersection, and aesthetic features.(3)

Comments:

• When raised intersections are integrated with the curb (same height as the curb), the transition from the sidewalk to the raised cross walk should be denoted by a slight lip or other device to warn the visually impaired.
• When designing raised intersections, considerable attention should be given to aesthetics.